The next generation of GOES-R and JPSS VIIRS imagers will have onboard visible calibration. The calibration of these sensors will need to be vicariously validated to ensure that the cloud or aerosol retrievals are of climate quality. The Global Space-based Inter-Calibration System (GSICS) is an international organization interested in consistent calibration among operational satellites. The preferred GSICS approach is to use a well-calibrated hyper-spectral instrument in order to directly transfer the calibration to the target sensor, while also accounting for the spectral response function (SRF) difference, with the use of coincident ray-matched radiances. The GSICS currently uses Aqua-MODIS as the visible absolute calibration reference. This approach is applied to calibrate IR operational sensors using the Infrared Atmospheric Sounding Interferometer (IASI) or the Atmospheric Infrared Sounder (AIRS) as the hyper-spectral reference instrument.

Envisat Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) hyper-spectral data have the potential to function as a transfer medium for the absolute calibration reference of the MODerate-resolution Imaging Spectroradiometer (MODIS) and geostationary satellite (GEO) imagers while being able to adjust for SRF differences. Spatially and temporally matched inter-calibrations of MODIS and GEO visible radiances have been developed using a ray-matching cross-calibration technique. The SCIAMACHY absolute calibration and stability are evaluated by cross-calibrating SCIAMACHY with Aqua-MODIS at the ground track intersects near the poles, thereby serving as a calibration transfer standard. Preliminary results indicate excellent calibration transfer given direct comparisons of Aqua-MODIS and SCIAMACHY-convolved-with-Aqua-MODIS-SRF radiances have standard errors of ~0.2% over a large dynamic range. Ideally, this technique can be used to calibrate the next generation of GOES-R and JPSS imagers.